The present invention relates to a melt spinning apparatus for extruding and spinning thermoplastic filaments, and of the type generally disclosed in DE 33 43 714 A1.
Extrusion spinning devices for spinning manmade fibers which have the spinning heads arranged in spinning beams are known in various designs from prior art--see, for example, U.S. Pat. No. 3,891,379, DE 33 43 714 A1, DE-GM 84 07 945 or EP-B 0 163 248. All, or at least most of the known spinning devices are of a technically elaborate design so as to achieve at least approximately identical operating conditions at the spinning units operated, in each case, by the same program. Such efforts are necessary and also customary for manufacturing high-quality multi-filament yarns. As a result, the necessary outlay for maintenance is also high.
From the initially cited DE 33 43 714 A1, an installation for double-sided, continuous spinning of manmade fibers is known, which has a double-sided spinning block. The spinning block comprises a closed, heated structural part, inserted in a penetrating manner into which are pipes, which are aligned vertically and in a row and accommodate spinning units each comprising a filter and a spinneret body. Housed in the spinning block are melt metering pumps (metering gear pumps), to which spinning melt is supplied through distribution lines from a melting extruder and which in turn feed the spinning melt to the spinning units. Of the melt metering pumps, however, it is, in each case, only the part containing the connections for the spinning melt which projects into the heated structural part or container.
Heating of the closed container is effected by an oil, described as diathermic in DE 33 43 714 A1, which is heated by electrical resistance heating elements and contained in a sump provided under the spinneret units. It is, however, only the parts situated in the closed interior of the spinning block which are heated.
The construction known from DE 33 43 714 A1 also has considerable drawbacks. The structural part comparable to a spinning beam is of a very fissured design which is very costly to manufacture. Also, as already mentioned, the melt metering pumps lie in the heat insulation and only partially inside the closed container. They are therefore only partially heated.
It is accordingly an object of the present invention to reduce the outlay required to manufacture as well as to operate and maintain the spinning units and achieve identical production conditions for all spinning units of the spinning apparatus.